The East London Business Alliance, a group of City businesses, has launched an email campaign asking their employees to volunteer for charity.
Charity Technology Trust, which provides technology support to the not-for-profit sector, has co-ordinated the initiative and has so far recruited more than 600 new volunteers.
Peter Sweatman, chief executive at Charity Technology Trust, said using email for employee recruitment had great potential.
"Email is an effective way of establishing communications," he said.
"With the initial East London Business Alliance test, we were easily able to find out what the employee wanted to get out of volunteering by asking a set of questions to which they could immediately respond."